https://docs.mendix.com/appstore/modules/community-commons-function-library/#49-stringutils
Community commons has a string split function, which returns a list of strings based on a regex.
For example, if you where to split your string using a space as a delimiter, you would get a list with :
12
34
ABCDEFGHIJKL
Maybe this can help you in showing the correct portion of your string? (depends if the portion you wish to show is always the third element in the resulting list,..)
A different approach might be:
find(12 34 ABCDEFGHIJKL, ‘[a-z]’) which will return a position in an integer.
Do the same with findlast(12 34 ABCDEFGHIJKL, ‘[a-z]’) and then substring the value in between. You might wanna use capital letters instead of lowercase (or just use the tolowercase function first)
Hope this helps!